 
 
var S = {
    init: function () {
      var action = window.location.href,
          i = action.indexOf('?a=');
   
      S.Drawing.init('.canvas');
      document.body.classList.add('body--ready');
   
      if (i !== -1) {
        S.UI.simulate(decodeURI(action).substring(i + 3));
      } else {
        S.UI.simulate('|#countdown 3||2023|兔年快乐！||#rectangle|');
        // S.UI.simulate('|写|尽|千|山|落|笔|是|你|#rectangle|');
      }
   
      S.Drawing.loop(function () {
        S.Shape.render();
      });
    }
  };
   
   
  S.Drawing = (function () {
    var canvas,
        context,
        renderFn
        requestFrame = window.requestAnimationFrame       ||
                       window.webkitRequestAnimationFrame ||
                       window.mozRequestAnimationFrame    ||
                       window.oRequestAnimationFrame      ||
                       window.msRequestAnimationFrame     ||
                       function(callback) {
                         window.setTimeout(callback, 1000 / 60);
                       };
   
    return {
      init: function (el) {
        canvas = document.querySelector(el);
        context = canvas.getContext('2d');
        this.adjustCanvas();
   
        window.addEventListener('resize', function (e) {
          S.Drawing.adjustCanvas();
        });
      },
   
      loop: function (fn) {
        renderFn = !renderFn ? fn : renderFn;
        this.clearFrame();
        renderFn();
        requestFrame.call(window, this.loop.bind(this));
      },
   
      adjustCanvas: function () {
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;
      },
   
      clearFrame: function () {
        context.clearRect(0, 0, canvas.width, canvas.height);
      },
   
      getArea: function () {
        return { w: canvas.width, h: canvas.height };
      },
   
      drawCircle: function (p, c) {
        context.fillStyle = c.render();
        context.beginPath();
        context.arc(p.x, p.y, p.z, 0, 2 * Math.PI, true);
        context.closePath();
        context.fill();
      }
    }
  }());
   
   
  S.UI = (function () {
    var canvas = document.querySelector('.canvas'),
        interval,
        isTouch = false, //('ontouchstart' in window || navigator.msMaxTouchPoints),
        currentAction,
        resizeTimer,
        time,
        maxShapeSize = 30,
        firstAction = true,
        sequence = [],
        cmd = '#';
   
    function formatTime(date) {
      var h = date.getHours(),
          m = date.getMinutes(),
      m = m < 10 ? '0' + m : m;
      return h + ':' + m;
    }
    function getValue(value) {
      return value && value.split(' ')[1];
    }
    function getAction(value) {
      value = value && value.split(' ')[0];
      return value && value[0] === cmd && value.substring(1);
    }
    function timedAction(fn, delay, max, reverse) {
      clearInterval(interval);
      currentAction = reverse ? max : 1;
      fn(currentAction);
      if (!max || (!reverse && currentAction < max) || (reverse && currentAction > 0)) {
        interval = setInterval(function () {
          currentAction = reverse ? currentAction - 1 : currentAction + 1;
          fn(currentAction);
          if ((!reverse && max && currentAction === max) || (reverse && currentAction === 0)) {
            clearInterval(interval);
          }
        }, delay);
      }
    }
    function reset(destroy) {
      clearInterval(interval);
      sequence = [];
      time = null;
      destroy && S.Shape.switchShape(S.ShapeBuilder.letter(''));
    }
    function performAction(value) {
      var action,
          value,
          current;
      // overlay.classList.remove('overlay--visible');
      sequence = typeof(value) === 'object' ? value : sequence.concat(value.split('|'));
      // input.value = '';
      // checkInputWidth();
      timedAction(function (index) {
        current = sequence.shift();
        action = getAction(current);
        value = getValue(current);
        switch (action) {
          case 'countdown':
            value = parseInt(value) || 10;
            value = value > 0 ? value : 10;
            timedAction(function (index) {
              if (index === 0) {
                if (sequence.length === 0) {
                  S.Shape.switchShape(S.ShapeBuilder.letter(''));
                } else {
                  performAction(sequence);
                }
              } else {
                S.Shape.switchShape(S.ShapeBuilder.letter(index), true);
              }
            }, 1000, value, true);
            break;
          case 'rectangle':
            value = value && value.split('x');
            value = (value && value.length === 2) ? value : [maxShapeSize, maxShapeSize / 2];
            S.Shape.switchShape(S.ShapeBuilder.rectangle(Math.min(maxShapeSize, parseInt(value[0])), Math.min(maxShapeSize, parseInt(value[1]))));
            break;
          case 'circle':
            value = parseInt(value) || maxShapeSize;
            value = Math.min(value, maxShapeSize);
            S.Shape.switchShape(S.ShapeBuilder.circle(value));
            break;
          case 'time':
            var t = formatTime(new Date());
            if (sequence.length > 0) {
              S.Shape.switchShape(S.ShapeBuilder.letter(t));
            } else {
              timedAction(function () {
                t = formatTime(new Date());
                if (t !== time) {
                  time = t;
                  S.Shape.switchShape(S.ShapeBuilder.letter(time));
                }
              }, 1000);
            }
            break;
          default:
            S.Shape.switchShape(S.ShapeBuilder.letter(current[0] === cmd ? 'What?' : current));
        }
      }, 2000, sequence.length);
    }
    function checkInputWidth(e) {
      if (input.value.length > 18) {
        ui.classList.add('ui--wide');
      } else {
        ui.classList.remove('ui--wide');
      }
      if (firstAction && input.value.length > 0) {
        ui.classList.add('ui--enter');
      } else {
        ui.classList.remove('ui--enter');
      }
    }
    function bindEvents() {
      document.body.addEventListener('keydown', function (e) {
        input.focus();
        if (e.keyCode === 13) {
          firstAction = false;
          reset();
          performAction(input.value);
        }
      });
      canvas.addEventListener('click', function (e) {
        overlay.classList.remove('overlay--visible');
      });
    }
    function init() {
      bindEvents();
      // input.focus();
      isTouch && document.body.classList.add('touch');
    }
    // Init
    init();
    return {
      simulate: function (action) {
        performAction(action);
      }
    }
  }());
  S.UI.Tabs = (function () {
    var tabs = document.querySelector('.tabs'),
        labels = document.querySelector('.tabs-labels'),
        triggers = document.querySelectorAll('.tabs-label'),
        panels = document.querySelectorAll('.tabs-panel');
    function activate(i) {
      triggers[i].classList.add('tabs-label--active');
      panels[i].classList.add('tabs-panel--active');
    }
    function bindEvents() {
      labels.addEventListener('click', function (e) {
        var el = e.target,
            index;
        if (el.classList.contains('tabs-label')) {
          for (var t = 0; t < triggers.length; t++) {
            triggers[t].classList.remove('tabs-label--active');
            panels[t].classList.remove('tabs-panel--active');
            if (el === triggers[t]) {
              index = t;
            }
          }
          activate(index);
        }
      });
    }
    function init() {
      activate(0);
      bindEvents();
    }
    // Init
    init();
  }());
  S.Point = function (args) {
    this.x = args.x;
    this.y = args.y;
    this.z = args.z;
    this.a = args.a;
    this.h = args.h;
  };
  S.Color = function (r, g, b, a) {
    this.r = r;
    this.g = g;
    this.b = b;
    this.a = a;
  };
  S.Color.prototype = {
    render: function () {
      return 'rgba(' + this.r + ',' +  + this.g + ',' + this.b + ',' + this.a + ')';
    }
  };
  S.Dot = function (x, y) {
    this.p = new S.Point({
      x: x,
      y: y,
      z: 5,
      a: 1,
      h: 0
    });
    this.e = 0.07;
    this.s = true;
    this.c = new S.Color(255, 255, 255, this.p.a);
    this.t = this.clone();
    this.q = [];
  };
  S.Dot.prototype = {
    clone: function () {
      return new S.Point({
        x: this.x,
        y: this.y,
        z: this.z,
        a: this.a,
        h: this.h
      });
    },
    _draw: function () {
      this.c.a = this.p.a;
      S.Drawing.drawCircle(this.p, this.c);
    },
    _moveTowards: function (n) {
      var details = this.distanceTo(n, true),
          dx = details[0],
          dy = details[1],
          d = details[2],
          e = this.e * d;
      if (this.p.h === -1) {
        this.p.x = n.x;
        this.p.y = n.y;
        return true;
      }
      if (d > 1) {
        this.p.x -= ((dx / d) * e);
        this.p.y -= ((dy / d) * e);
      } else {
        if (this.p.h > 0) {
          this.p.h--;
        } else {
          return true;
        }
      }
      return false;
    },
    _update: function () {
      if (this._moveTowards(this.t)) {
        var p = this.q.shift();
        if (p) {
          this.t.x = p.x || this.p.x;
          this.t.y = p.y || this.p.y;
          this.t.z = p.z || this.p.z;
          this.t.a = p.a || this.p.a;
          this.p.h = p.h || 0;
        } else {
          if (this.s) {
            this.p.x -= Math.sin(Math.random() * 3.142);
            this.p.y -= Math.sin(Math.random() * 3.142);
          } else {
            this.move(new S.Point({
              x: this.p.x + (Math.random() * 50) - 25,
              y: this.p.y + (Math.random() * 50) - 25,
            }));
          }
        }
      }
      d = this.p.a - this.t.a;
      this.p.a = Math.max(0.1, this.p.a - (d * 0.05));
      d = this.p.z - this.t.z;
      this.p.z = Math.max(1, this.p.z - (d * 0.05));
    },
    distanceTo: function (n, details) {
      var dx = this.p.x - n.x,
          dy = this.p.y - n.y,
          d = Math.sqrt(dx * dx + dy * dy);
      return details ? [dx, dy, d] : d;
    },
    move: function (p, avoidStatic) {
      if (!avoidStatic || (avoidStatic && this.distanceTo(p) > 1)) {
        this.q.push(p);
      }
    },
    render: function () {
      this._update();
      this._draw();
    }
  }
  S.ShapeBuilder = (function () {
    var gap = 13,
        shapeCanvas = document.createElement('canvas'),
        shapeContext = shapeCanvas.getContext('2d'),
        fontSize = 500,
        fontFamily = 'Avenir, Helvetica Neue, Helvetica, Arial, sans-serif';
    function fit() {
      shapeCanvas.width = Math.floor(window.innerWidth / gap) * gap;
      shapeCanvas.height = Math.floor(window.innerHeight / gap) * gap;
      shapeContext.fillStyle = 'red';
      shapeContext.textBaseline = 'middle';
      shapeContext.textAlign = 'center';
    }
    function processCanvas() {
      var pixels = shapeContext.getImageData(0, 0, shapeCanvas.width, shapeCanvas.height).data;
          dots = [],
          pixels,
          x = 0,
          y = 0,
          fx = shapeCanvas.width,
          fy = shapeCanvas.height,
          w = 0,
          h = 0;
      for (var p = 0; p < pixels.length; p += (4 * gap)) {
        if (pixels[p + 3] > 0) {
          dots.push(new S.Point({
            x: x,
            y: y
          }));
          w = x > w ? x : w;
          h = y > h ? y : h;
          fx = x < fx ? x : fx;
          fy = y < fy ? y : fy;
        }
        x += gap;
        if (x >= shapeCanvas.width) {
          x = 0;
          y += gap;
          p += gap * 4 * shapeCanvas.width;
        }
      }
      return { dots: dots, w: w + fx, h: h + fy };
    }
    function setFontSize(s) {
      shapeContext.font = 'bold ' + s + 'px ' + fontFamily;
    }
    function isNumber(n) {
      return !isNaN(parseFloat(n)) && isFinite(n);
    }
    function init() {
      fit();
      window.addEventListener('resize', fit);
    }
    // Init
    init();
    return {
      imageFile: function (url, callback) {
        var image = new Image(),
            a = S.Drawing.getArea();
        image.onload = function () {
          shapeContext.clearRect(0, 0, shapeCanvas.width, shapeCanvas.height);
          shapeContext.drawImage(this, 0, 0, a.h * 0.6, a.h * 0.6);
          callback(processCanvas());
        };
        image.onerror = function () {
          callback(S.ShapeBuilder.letter('What?'));
        }
        image.src = url;
      },
      circle: function (d) {
        var r = Math.max(0, d) / 2;
        shapeContext.clearRect(0, 0, shapeCanvas.width, shapeCanvas.height);
        shapeContext.beginPath();
        shapeContext.arc(r * gap, r * gap, r * gap, 0, 2 * Math.PI, false);
        shapeContext.fill();
        shapeContext.closePath();
        return processCanvas();
      },
      letter: function (l) {
        var s = 0;
        setFontSize(fontSize);
        s = Math.min(fontSize,
                    (shapeCanvas.width / shapeContext.measureText(l).width) * 0.8 * fontSize,
                    (shapeCanvas.height / fontSize) * (isNumber(l) ? 1 : 0.45) * fontSize);
        setFontSize(s);
        shapeContext.clearRect(0, 0, shapeCanvas.width, shapeCanvas.height);
        shapeContext.fillText(l, shapeCanvas.width / 2, shapeCanvas.height / 2);
        return processCanvas();
      },
      rectangle: function (w, h) {
        var dots = [],
            width = gap * w,
            height = gap * h;
        for (var y = 0; y < height; y += gap) {
          for (var x = 0; x < width; x += gap) {
            dots.push(new S.Point({
              x: x,
              y: y,
            }));
          }
        }
        return { dots: dots, w: width, h: height };
      }
    };
  }());
  S.Shape = (function () {
    var dots = [],
        width = 0,
        height = 0,
        cx = 0,
        cy = 0;
    function compensate() {
      var a = S.Drawing.getArea();
      cx = a.w / 2 - width / 2;
      cy = a.h / 2 - height / 2;
    }
    return {
      shuffleIdle: function () {
        var a = S.Drawing.getArea();
        for (var d = 0; d < dots.length; d++) {
          if (!dots[d].s) {
            dots[d].move({
              x: Math.random() * a.w,
              y: Math.random() * a.h
            });
          }
        }
      },
      switchShape: function (n, fast) {
        var size,
            a = S.Drawing.getArea();
        width = n.w;
        height = n.h;
        compensate();
        if (n.dots.length > dots.length) {
          size = n.dots.length - dots.length;
          for (var d = 1; d <= size; d++) {
            dots.push(new S.Dot(a.w / 2, a.h / 2));
          }
        }
        var d = 0,
            i = 0;
        while (n.dots.length > 0) {
          i = Math.floor(Math.random() * n.dots.length);
          dots[d].e = fast ? 0.25 : (dots[d].s ? 0.14 : 0.11);
          if (dots[d].s) {
            dots[d].move(new S.Point({
              z: Math.random() * 20 + 10,
              a: Math.random(),
              h: 18
            }));
          } else {
            dots[d].move(new S.Point({
              z: Math.random() * 5 + 5,
              h: fast ? 18 : 30
            }));
          }
          dots[d].s = true;
          dots[d].move(new S.Point({
            x: n.dots[i].x + cx,
            y: n.dots[i].y + cy,
            a: 1,
            z: 5,
            h: 0
          }));
          n.dots = n.dots.slice(0, i).concat(n.dots.slice(i + 1));
          d++;
        }
        for (var i = d; i < dots.length; i++) {
          if (dots[i].s) {
            dots[i].move(new S.Point({
              z: Math.random() * 20 + 10,
              a: Math.random(),
              h: 20
            }));
            dots[i].s = false;
            dots[i].e = 0.04;
            dots[i].move(new S.Point({
              x: Math.random() * a.w,
              y: Math.random() * a.h,
              a: 0.3, //.4
              z: Math.random() * 4,
              h: 0
            }));
          }
        }
      },
      render: function () {
        for (var d = 0; d < dots.length; d++) {
          dots[d].render();
        }
      }
    }
  }());
  S.init();